public class java0723 {
    public static void main(String[] args) {


        String a1 = "abc";
        String a2 = "abc";
        System.out.println(a1 == a2);

        int b = 100;
        String str = String.valueOf(b);
        System.out.println(str);//一种方法



        int i = a1.indexOf('c');//返回字母下标
        System.out.println(i);

    }


}
